There are several ways heat can be shared. One of the most commonly used for heating rooms is to use convection. When air is heated it rises. When air cools it sinks. This is used in a convector heater to make air circulate in a room. The heater is placed in a metal case that works like a tower. Air is heated in the 'tower' and it rises out into the room. This sucks in cold air through the bottom of the tower. The cold air is heated in turn, causing it to rise and suck in yet more cold air.

Convection is also used to heat water evenly in a pan. The water is heated from below, it gets hot and rises, causing a circulation that pushes cold water down to be heated in turn.